The angle of elevation of the top of an unfinished pillar from a point 150 metres from its base is 30°. The height (in metres) that the pillar must be raised so that its angle of elevation at the same point may be 45°, is (taking √3 = 1.732)

• A. 63.4
• B. 86.6
• C. 126.8
• D. 173.2